Horniella haucki Zhang & Yin, 2021

Zhang, Wen-Xuan, Hu, Fang-Shuo & Yin, Zi-Wei, 2021, Six new species of Horniella Raffray from the Oriental region (Coleoptera, Staphylinidae, Pselaphinae), ZooKeys 1042, pp. 1-22 : 1

Horniella haucki Zhang & Yin sp. nov. Figures 1B , 3

Type material.

Holotype: Thailand: ♂, 'THAI, N, Mae Hong Son prov., SE of Soppong, 1500 m, 19°27'N, 98°20'E, 23-27.v.1999, D. Hauck leg.' (MHNG).

Diagnosis.

Male. Head longer than wide, with distinct anterolateral genal projection, anterior margin of projection roundly emarginate; with long ocular canthus; scape angularly expanded at basolateral margin, antennomeres 9-11 moderately enlarged. Pronotum rounded at anterolateral margins. Protrochanter and profemur each with long ventral spine; protibia strongly curved near apex, with long apical projection; mesotrochanter with large sharp ventral spine, mesofemur distinctly arched. Tergite 1 (IV) with median carina extending posteriorly for approximately 3/4 of tergal length, discal carinae short and thin. Aedeagus with asymmetric median lobe, left half of median lobe greatly protruding in dorso-ventral view; endophallus composed of three long sclerites.

Description.

Male. Body reddish-brown, length 3.49 mm. Head (Fig. 3A ) slightly longer than wide, HL 0.75 mm, HW 0.7 mm; anterolateral genal projection distinct, anterior margin of projection roundly emarginate; antenna 1.95 mm long, scape angularly expanded at basolateral margin, antennomeres 2-7 slightly elongate, antennomere 8 as long as wide, club loosely formed by apical three moderately enlarged antennomeres, antennomere 11 largest, approximately as long as antennomeres 9 and 10 combined; indistinct lateral postantennal pits present; eyes prominent, each composed of approximately 40 large facets, with long ocular canthi (Fig. 3B ).

Pronotum longer than wide, PL 0.74 mm, PW 0.69 mm, widest at apical 1/3; anterolateral margins rounded; disc moderately convex, finely punctate, with distinct median antebasal and lateral antebasal foveae connected by complete transverse antebasal sulcus.

Elytra much wider than long, EL 0.95 mm, EW 1.35 mm; each elytron with two large, setose basal foveae; discal striae extending from outer basal foveae to apical 2/3 of elytral length.

Legs elongate; protrochanter (Fig. 3C ) with distinct ventral spine, profemur (Fig. 3C ) with long ventral spine near base, protibia (Fig. 3D ) strongly curved near apex, with long apical projection; mesotrochanter (Fig. 3E ) with long sharp ventral spine, mesofemur (Fig. 3E ) strongly arched at middle, mesotibia (Fig. 3F ) strongly curved near apex, with small triangular spur.

Abdomen slightly broader than long, broadest at lateral margins of tergite 1 (IV), AL 1.05 mm, AW 1.32 mm; tergite 1 (IV) largest, as long as tergites 2 and 3 (V and VI) combined, with median carina extending to near basal 3/5 of tergal length, discal carinae short and thin, tergite 2 (V) lacking carina, tergites 2-4 (V-VII) each with small basolateral foveae. Sternite 2 (IV) with broad basal sulcus, lacking mediobasal foveae, basolateral foveae developed as large cuticular pockets, with two pairs of antebasal nodules, sternites 3-5 (V-VII) with basolateral foveae, one median and two lateral nodules, sternite 7 (IX) with well-sclerotized apical half, and membranous basal half.

Aedeagus (Fig. 3G-I ) 0.69 mm long, with asymmetric median lobe, left half of median lobe greatly protruding in dorsal view; endophallus composed of three elongate sclerites close to each other.

Female. Unknown.

Comparative notes.

This new species can be readily separated from all members of the H. centralis group primarily by the characteristic shape of the aedeagus, especially the form of the apical portion of the median lobe, and the configuration of the endophallus.

Distribution.

Thailand: Mae Hong Son.

Etymology.

The new species is named after David Hauck ( České Budějovice, Czech Republic), collector of the holotype.

Figures

Figure 1. Dorsal habitus of Horniella species A H. bifurca sp. nov. B H. haucki sp. nov. Scale bars: 1 mm.

Figure 3. Diagnostic characters of Horniella haucki sp. nov. A left half of head, in dorsal view B head, in lateral view C protrochanter and profemur D protibia E mesotrochanter and mesofemur F mesotibia G-I aedeagus, in dorsal (G), lateral (H), and ventral (I) view. Scale bars: 0.3 mm (A, C-F); 0.2 mm (B, G-I).